Figure 2. SGO1 is a potential transcriptional target of MYCN.

(a) MYCN overexpression induced SGO1 mRNA (left) and protein (right) expression in SH-EP cells (MYCN single-copy neuroblastoma cell line). (b) SGO1 protein levels were reduced in MYCN-downregulated IMR32 cells, but the SMC3 protein level was unchanged in these cells. Samples were harvested 3 days after non-target or MYCN-targeted shRNA lentivirus infection. Quantification of proteins on Western blots using ImageJ software. (c) Positions of E-box sequences associated with SGO1. Black circles, E-boxes; white boxes, 5′- or 3′-UTRs; gray boxes, exons. (d) ChIP analysis revealed enrichment of MYCN in E-box1 and E-box2 upstream of SGO1. A sequence 20 kb upstream of the SGO1 gene was used as a negative control. Data show the percentage of target DNA precipitated with control IgG or MYCN antibody, and are expressed as the means ± SE of at least three independent experiments.